class Solution {
public:
    
    bool isValidSudoku(vector<vector<char>>& board) {
        bool row[9][10] = { false };
        bool col[9][10] = { false };
        bool b[3][3][10] = { false };
        for(int i = 0; i < 9; i++)
        {
            for(int j = 0; j < 9; j++)
            {  
                if(board[i][j] != '.')
                {
                    int num = board[i][j] - '0';    
                    if(row[i][num] || col[j][num] || b[i/3][j/3][num])
                        return false;
                    row[i][num] = true;
                    col[j][num] = true;
                    b[i/3][j/3][num] = true;
                }
            }
        }
        return true;
    }
};